A number of different video encoding standards have been established for coding digital multimedia sequences. The Moving Picture Experts Group (MPEG), for example, has developed a number of standards including MPEG-1, MPEG-2 and MPEG-4. Other examples include the International Telecommunication Union (ITU) H.263 standard, and the emerging ITU H.264 standard, which is also set forth in MPEG-4 Part 10, entitled “Advanced Audio Coding.” These video coding standards generally support improved transmission efficiency of multimedia sequences by coding data in a compressed manner. Compression reduces the overall amount of data that needs to be transmitted for effective transmission of multimedia frames. Video coding is used in many contexts, including video streaming, video camcorder, video telephony (VT) and video broadcast applications, over both wired and wireless transmission media.
The MPEG-4, ITU H.263 and ITU H.264 standards, in particular, support video coding techniques that utilize similarities between successive multimedia frames, referred to as temporal or inter-frame correlation, to provide Inter-frame compression. The inter-frame compression techniques exploit data redundancy across frames by converting pixel-based representations of multimedia frames to motion representations. Frames coded using inter-frame techniques are often referred to as P (“predictive”) frames or B (“bi-directional”) frames. Some frames, commonly referred to as I (“intra”) frames, are coded using spatial compression, which is non-predictive. In addition, some frames may include a combination of both intra- and inter-coded blocks.
Transitional effects can present challenges in video coding, particularly when inter-frame compression is used. Transitional effects refer to visual video effects that are used to transition from a current scene of a multimedia sequence. Transitional effects include fading effects, dissolving effects, sliding effects, breaking effects, flipping effects, and a wide range of other types of visual effects used to transition away from a current scene. Often, the transitional effects are used to change from a first scene to a second scene, such as by fading or dissolving the first scene into the second scene. However, the transitional effects may also be used in other contexts, such as by fading or dissolving the last scene of a sequence to an empty scene in order to signify the end of that multimedia sequence.